SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf3f65a09dd44a282af75aa436c0b7c41c5f089c8394a8c0b91c122efa934e1a' 
  AND token = 'E3P4HncYH9X3zKLB42BVH7n45fnjwcBgqfSUtJgNjng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}